At first, it struck fans of both bands as an odd choice. Kool and the Gang warming up crowds for the latest version of Van Halen? What did the Jersey City funk and boogie masters have to do with a classic rock band on its umpteenth arena circuit?

Quite a bit, as it has turned out. David Lee Roth’s decision to tap Kool and the Gang as tourmates was a shrewd one.

“He saw us at the Glastonbury Festival in England,” says Robert “Kool” Bell, 61. “David said, ‘Hey, our audience is 60 percent women. You guys wrote “Ladies’ Night.” Let’s have a party.’ ”

The tour comes to Atlantic City on Saturday, striking another blow against musical segregation. As Roth surmised, there is more overlap between the audiences of the two acts than either might initially acknowledge. Chances are, if you were at a shindig in the ’70s or early ’80s — and if it was any good — you heard both Van Halen and Kool and the Gang on the record player.

“They were like the rock party band,” says Kool, “and we were like the pop-funk party band. When Van Halen was starting out, they used to play our music in the clubs of L.A. before they’d go onstage.”

At the two Van Halen shows at Madison Square Garden in February, Kool and the Gang — who have sold more that 70 million records — won over a skeptical hard-rock crowd with their showmanship, their hard grooves and their willingness to engage with the audience.

“In the beginning, you could see the diehards in the crowd. They refused to clap their hands. When we did the AOR song ‘Misled,’ they said, ‘Okay, these guys can rock a little, too.’ When we got to ‘Hollywood Swingin’,’ people were singing along. And by the time we got to ‘Ladies’ Night,’ the ladies were jumping up and down and partying, and their guys were like, ‘What’s the matter with you?’

“And then they started dancing, too.”

With anywhere from 10 to 12 musicians gyrating onstage, the band looks like a party, too. Forty years after the group’s formation, Kool and the Gang remains a whirlwind in concert, with members dancing, switching microphones and doing flashy calisthenics with brass instruments in hand.

Although the group has talent to burn, it’s Kool who makes the groove sound so ferocious. His thick, driving bass guitar — one with a signal as bright and clear as a full moon — frequently fills the role of a lead instrument. Even when it doesn’t, it’s the spindle that the rest of the band winds around.

“I think it’s in my hands and how I play,” says Kool of his distinctive sound. “I was self-taught, and I kind of created my own style. When we first started out, we were backing up all of these groups in Jersey City, and I had to learn all the bass lines to the Motown hits. And I always loved jazz. Ron Carter and Reggie Workman were big influences on me.”

Kool and his brother Ronald Khalis Brown— the group’s saxophonist and co-founder — were born in Youngstown, Ohio, to Bobby Bell, a ranked welterweight boxer who was a friend of Thelonious Monk’s. Theirs was a jazz household, and after relocating to Hudson County, the teenage Bells put together their own jazz combo. But there was just as much work to be found supporting R&B and pop singers, and the group that eventually became Kool and the Gang gigged all over Jersey City, performing in Journal Square and Lincoln Park, and at proms and private parties.

Yet the jazz sensibility never vanished from the group’s music. It took Kool and the Gang more than 10 years to hire a permanent lead vocalist. In the ’70s, the band’s appeal was all about the alchemy between its musicians. When Kool and his collaborators locked into a groove, the band’s creative fertility astonished even its members.

“In ’73, we went to a studio in Soho to play and write,” said Kool. “We began at 8 in the morning and jammed all day. By 10 that night, we’d come up with ‘Hollywood Swinging,’ ‘Funky Stuff’ and ‘Jungle Boogie.’ It was just magic.”

George Clinton and his Parliament and Funkadelic groups are often rightly credited for supplying much of the raw material that hip-hop producers would later shape into hit records. Kool and the Gang are responsible for nearly as much. Rappers from the hardcore (N.W.A, Eric B & Rakim) to the frothy (Will Smith, Mase) have fashioned landmark records out of Kool’s irresistible grooves.

“It’s all cool, depending on how they use it,” says Kool. “When it first started happening, we were happy about it. As long as we got paid for that!”